Start with the question, not a target number
Exploratory interviews help you understand how people describe a problem, what they do about it, and why their choices make sense to them. They are useful when you do not yet know which questions belong in a survey or which assumptions deserve testing. The goal is to uncover possibilities and build a clearer picture, not to estimate how common an opinion is across a market.
Before deciding how many people to interview, write down the decision the study will inform. Are you trying to improve an onboarding experience, understand why customers switch providers, or identify situations in which a product is not useful? A narrow question can often be explored with fewer conversations than a broad investigation involving several types of customers. An interview count is a planning tool, not a guarantee that the study will answer every question.
Plan around meaningful differences between customers
Who you interview matters at least as much as how many interviews you conduct. If you speak only with your most engaged customers, you may miss the obstacles faced by new users or people who left. List the differences that could plausibly change someone’s experience: familiarity with the product, reason for using it, buying role, or stage in the customer journey. Choose a small set that is relevant to your research question rather than trying to represent every possible profile.
For a focused, fairly similar group, you might begin with a handful of interviews and review what you have learned before recruiting more. If the study covers distinct groups, plan enough conversations within each group to compare their experiences without treating one person as the voice of an entire segment. Do not merge unlike participants into a single total and assume the resulting number makes every perspective well understood.
Use an initial round, then reassess
A flexible plan is often more useful than committing to one final number at the outset. Set an initial round that fits your time and recruitment capacity. After those interviews, summarize each participant’s situation, actions, obstacles, and desired outcome. Look across the notes for patterns, contradictions, and questions you failed to ask clearly. This checkpoint helps you decide whether the next interview should involve someone similar or someone with a different experience.
Ask what new interviews are likely to change. If participants keep describing a workflow you had not anticipated, more conversations may help explain its variations. If one unusual account conflicts with the rest, another interview with a comparable customer may clarify whether it points to a distinct need. If the findings are already clear enough to guide a limited next step, continuing to interview simply to reach a round number may not be the best use of your time.
Know what a stopping point can and cannot mean
Researchers sometimes stop when additional interviews no longer reveal important new themes. That can be a helpful signal, but it depends on whom you recruited and how well your questions encouraged specific stories. Repetition among a narrow group does not show that you have heard every relevant customer perspective. A weak interview guide can also produce repetitive answers because it keeps steering people toward the same topics.
A practical stopping rule is to ask whether another interview is likely to affect the decision at hand. Check whether you have heard from the customer types most relevant to that decision, explored major disagreements, and identified the limits of your sample. If not, recruit deliberately to fill those gaps. If so, document what you learned and what remains uncertain. You can always return to interviews when a later decision calls for a different perspective.
Report insights without overstating them
Interview findings are strongest when they show how and why something happens. For example, you might learn that customers interpret a setup instruction in different ways and see where confusion enters the process. You should not turn a few interviews into a claim that a particular percentage of customers are confused. If prevalence matters, consider a suitable quantitative study after the interviews help you define what to measure.
When sharing results, describe who participated, how they were selected, and which perspectives may be missing. Separate observations from interpretations and proposed actions. A small, well-targeted exploratory study can be valuable when it reveals a problem worth investigating or gives a team a concrete change to try. The right number of interviews is therefore the number needed to make that next step more informed, while remaining honest about what the conversations cannot establish.
